Things to do in the winter

Shovel your sidewalk (it's not just a good idea, it's the law)
Bet with your coworkers on how late the bus will be
Buy wool socks, boots, and long johns
Go cross country skiing
Make a snowman
Visit the Hands on Museum
Check out the view from the top of a parking structures
Get hot chocolate
If it's 50º in December again, go rollerblading
Take a tour of holiday lights (they're not Christmas lights here)
Take advantage of Midnight Madness
Make a wood fire
Go to a UMS performance, or visit The Ark
Run from club to club in your short skirt and long jacket.
Swim in the Huron, or go ice fishing (no! don't!)
Buy apple cider from the Farmer's Market, and heat it up (or do the same with wine)
Go to Open Swim at one of the Indoor Pools
Visit the Matthaei Botanical Gardens and hang out in the conservatory.